Solar company LDK (LDK) predicts it will put up numbers this year that could shine a light on exchange traded funds (ETFs).

The company offered an upbeat 2009 revenue outlook, because its expansion of wafer production is ahead of schedule, according to the Associated Press. Analysts expect its full-year revenue to hit $2.43 billion next year.

The solar industry is growing, and it’s probably equal parts out of necessity (rising energy costs) and desire (concern about the environment). Whatever the reason, more companies and institutions are looking into how they can use solar power.

General Motors (GM) said it will install solar panels on the roof of its transmission assembly plant in Maryland, which will allow them displace 20% of the power it buys from a local utility, reports the Associated Press. Once installed, it will generate enough power to run about 140-150 homes for a year.

Big box stores are taking advantage of their size to get tax breaks by installing solar panels on their roofs in order to generate electricity.

Even schools are starting to get in on the action: Tallahassee, FL, and Leon County Schools are working together on a solar-school pilot project at Oak Ridge Elementary, reports Tamaryn Waters for the Tallahassee Democrat. If the project is a success, other schools in the district will go solar, too.

• Claymore/MAC Global Solar Energy (TAN): up 1% since April 15 inception; LDK is 5.1%
• Market Vectors Solar Energy (KWT): down 2.4% since April 23 inception; LDK is 4%

Tags: Energy, Green ETFs, KWT, Solar, TAN